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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

41193 results found.

  1. GRB 990506 optical observations
  2. GRB 990506 optical observations
  3. GRB 990506, optical observations
  4. GRB990506 observation plan
  5. Refined IPN error box for GRB990506
  6. GRB 990506: Limits on the possible optical transient
  7. GRB 990506, armchair astronomy
  8. GRB 990506, optical observations from +1 to +3 hours
  9. GRB 990506, optical observations
  10. GRB990506 Optical observations
  11. GRB990506 observation plan
  12. New IPN/RXTE error box for GRB990506
  13. IPN localization for GRB990506
  14. GRB 970228: Redshift and properties of the host galaxy
  15. IPN localization of GRB990427
  16. GRB981220 VLBA observations
  17. GRB980425 Optical observations of exponential decline at late time
  18. GRB990321 REFINED IPN ANNULUS
  19. GRB990323 PRECISE IPN POSITION
  20. GRB990321 IPN TRIANGULATION
  21. GRB 990316 Optical Observations
  22. GRB 990316, Radio observations
  23. GRB 990316, Optical observations
  24. GRB990316, Optical observations
  25. GRB 990316 optical observations
  26. GRB990316: simultaneous optical observation
  27. GRB990316 - Optical null results
  28. ASM/IPN error box for GRB 990308 (BATSE #7457)
  29. GRB 990308a and GRB 990308b
  30. GRB990308 (Trig. 7457), optical observations
  31. GRB990308, Possible new SGR~0209+70
  32. GRB981220, IPN localization
  33. GRB 981220, radio observations
  34. GRB 990123, Field Photometry
  35. GRB 990217 Optical Observations
  36. GRB 990217, radio observations
  37. BATSE Resumes Normal Operations
  38. BATSE Flight Anomaly
  39. GRB990217: BeppoSAX/GRBM data
  40. Optical Observations of GRB990217
  41. GRB990123 observations
  42. GRB990217 Optical observation
  43. GRB990217, WFC position
  44. GRB990123, Optical Observation
  45. GRB 990123: Discovery of the Probable Host Galaxy
  46. GRB 990123: Reduced HST Images
  47. GRB19990123 observations
  48. GRB 990123: BVRI standards in the field
  49. GRB 990123: Updated Keck Spectroscopy Results
  50. GRB981220, field photometry
  51. GRB 990123 NOT Spectrum Update
  52. GRB990123, Optical observation
  53. GRB990123, is the "radio flare" due to an inhomogeneous medium?
  54. GRB 990123: Publicly available reduced HST images
  55. GRB990123, Upcoming HST Service Observations
  56. GRB990123, 15-GHz limits
  57. GRB 990123: New Constraints on Possible Foreground Galaxies
  58. GRB990123 Optical Observations
  59. GRB990123, Probability of gravitational lensing
  60. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  61. GRB 990123: Continued Radio Observations
  62. GRB990123, Preliminary Lens Search Results
  63. On the Lensing Interpretation of GRB 990123
  64. Search for Potential Images of GRB 990123
  65. Search for Potential Images of GRB 990123
  66. GRB990123, Optical BVRI Observations
  67. GRB 990123: near-infrared observations.
  68. GRB990123, OSSE observations
  69. GRB 990123: Strong MeV CGRO-COMPTEL detection now posted on WWW
  70. GRB990123: NIR Observation
  71. GRB990123, ASCA X-ray observation of afterglow
  72. "GRB 990123: New BV Observations"
  73. GRB 990123 Optical Follow-Up
  74. GRB 990123; Addendum to GCN 223
  75. GRB 990123: BATSE Observations
  76. GRB 990123 Keck Spectrum update
  77. GRB990123 IPN annulus
  78. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  79. GRB990123 Optical Observations
  80. GRB 990123 Spectroscopic Redshifts
  81. GRB 990123: New Optical Observations, Decay Measure
  82. GRB 990123 Optical Follow-Up
  83. GRB 990123: Possible Gravitationally Lensed Burst?
  84. GRB990123, optical observation
  85. GRB 990123 optical observations
  86. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  87. GRB 990123 radio observations
  88. GRB 990123, new radio source
  89. GRB990123 optical observations
  90. GRB990123, Optical observation
  91. GRB 990123: Optical Decay Slope
  92. GRB 990123 r-band photometry
  93. GRB 990123 Optical Follow-up
  94. GRB990123, early optical counterpart detection
  95. GRB990123 Optical Observation
  96. GRB990123, refined SAX-WFC position
  97. GRB 990123: Bright New Source, Possible Optical Transient
  98. GRB 990123, Radio observations
  99. GRB990123, BeppoSAX WFC detection and NFI planned follow-up
  100. SN 1999E & GRB 980919

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